[Chat][Feature]Storage Implementation with Tree based data structure (#531)

azure-communication-ui/chat/src/main/java/com/azure/android/communication/ui/chat/repository/MessageRepository.kt

@@ -4,6 +4,10 @@
 package com.azure.android.communication.ui.chat.repository
 
 import com.azure.android.communication.ui.chat.models.MessageInfoModel
+import com.azure.android.communication.ui.chat.repository.storage.MessageRepositoryListReader
+import com.azure.android.communication.ui.chat.repository.storage.MessageRepositoryListWriter
+import com.azure.android.communication.ui.chat.repository.storage.MessageRepositoryTreeReader
+import com.azure.android.communication.ui.chat.repository.storage.MessageRepositoryTreeWriter
 
 internal class MessageRepository private constructor(
     val readerDelegate: MessageRepositoryReader,
@@ -31,5 +35,14 @@ internal class MessageRepository private constructor(
                 writerDelegate = writer
             )
         }
+
+        fun createTreeBackedRepository(): MessageRepository {
+            val writer = MessageRepositoryTreeWriter()
+            val reader = MessageRepositoryTreeReader(writer)
+            return MessageRepository(
+                readerDelegate = reader,
+                writerDelegate = writer
+            )
+        }
     }
 }

azure-communication-ui/chat/src/main/java/com/azure/android/communication/ui/chat/repository/storage/MessageRepositoryListStorage.kt

@@ -1,7 +1,12 @@
-package com.azure.android.communication.ui.chat.repository
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.android.communication.ui.chat.repository.storage
 
 import com.azure.android.communication.ui.chat.models.EMPTY_MESSAGE_INFO_MODEL
 import com.azure.android.communication.ui.chat.models.MessageInfoModel
+import com.azure.android.communication.ui.chat.repository.MessageRepositoryReader
+import com.azure.android.communication.ui.chat.repository.MessageRepositoryWriter
 import java.util.Collections
 
 internal class MessageRepositoryListWriter : MessageRepositoryWriter {

azure-communication-ui/chat/src/main/java/com/azure/android/communication/ui/chat/repository/storage/MessageRepositoryTreeStorage.kt

@@ -0,0 +1,118 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.android.communication.ui.chat.repository.storage
+
+import com.azure.android.communication.ui.chat.models.EMPTY_MESSAGE_INFO_MODEL
+import com.azure.android.communication.ui.chat.models.MessageInfoModel
+import com.azure.android.communication.ui.chat.repository.MessageRepositoryReader
+import com.azure.android.communication.ui.chat.repository.MessageRepositoryWriter
+import java.util.TreeMap
+
+internal class MessageRepositoryTreeWriter : MessageRepositoryWriter {
+
+    private val treeMapStoragePointer: TreeMap<Long, String> = TreeMap()
+    private val treeMapStorage: TreeMap<String, MessageInfoModel> = TreeMap()
+
+    val size: Int
+        get() = treeMapStorage.size
+
+    override fun addLocalMessage(messageInfoModel: MessageInfoModel) {
+        val orderId: Long = getOrderId(messageInfoModel)
+
+        messageInfoModel.id?.let { treeMapStoragePointer.put(orderId, it) }
+        messageInfoModel.id?.let { treeMapStorage.put(it, messageInfoModel) }
+    }
+
+    override fun addPage(page: List<MessageInfoModel>) {
+        page.forEach { it -> addLocalMessage(it) }
+    }
+
+    override fun addServerMessage(message: MessageInfoModel) {
+        addLocalMessage(message)
+    }
+
+    override fun removeMessage(message: MessageInfoModel) {
+        val orderId = getOrderId(message)
+
+        if (treeMapStoragePointer.contains(orderId)) {
+            treeMapStoragePointer.remove(orderId)
+            treeMapStorage.remove(message.id)
+        }
+    }
+
+    override fun editMessage(message: MessageInfoModel) {
+        val orderId = getOrderId(message)
+
+        if (treeMapStoragePointer.contains(orderId)) {
+            treeMapStorage.get(message.id)?.let { mergeWithPreviousMessage(it, message) }
+        } else {
+            addLocalMessage(message)
+        }
+    }
+
+    override fun getLastMessage(): MessageInfoModel? {
+        val key = treeMapStoragePointer.lastKey()
+        return treeMapStorage.get(treeMapStoragePointer.get(key))!!
+    }
+
+    fun searchItem(kth: Int): MessageInfoModel {
+
+        var highestKey = treeMapStoragePointer.lastKey() + 1
+        var lowestKey = treeMapStoragePointer.firstKey()
+        var elements = 0
+        var midKey: Long = 0
+        while (lowestKey <= highestKey) {
+            midKey = (highestKey + lowestKey).div(2)
+
+            elements = treeMapStoragePointer.headMap(midKey).size
+
+            if (elements < kth) {
+                lowestKey = midKey + 1
+            } else if (elements > kth) {
+                highestKey = midKey - 1
+            } else {
+                break
+            }
+        }
+
+        val key = treeMapStoragePointer.headMap(midKey).lastKey()
+        return treeMapStorage.get(treeMapStoragePointer.get(key))!!
+    }
+
+    private fun getOrderId(message: MessageInfoModel): Long {
+        return message.id?.toLong() ?: 0
+    }
+
+    private fun mergeWithPreviousMessage(
+        previousMessage: MessageInfoModel,
+        message: MessageInfoModel
+    ): MessageInfoModel {
+        var newMessage = MessageInfoModel(
+            id = previousMessage.id,
+            internalId = previousMessage.internalId,
+            content = message.content,
+            messageType = previousMessage.messageType,
+            version = previousMessage.version,
+            senderDisplayName = previousMessage.senderDisplayName,
+            createdOn = previousMessage.createdOn,
+            editedOn = previousMessage.editedOn,
+            deletedOn = previousMessage.deletedOn,
+            senderCommunicationIdentifier = previousMessage.senderCommunicationIdentifier,
+            isCurrentUser = previousMessage.isCurrentUser,
+        )
+        return newMessage
+    }
+}
+
+internal class MessageRepositoryTreeReader(private val writer: MessageRepositoryTreeWriter) : MessageRepositoryReader() {
+
+    override val size: Int
+        get() = writer.size
+
+    override fun get(index: Int): MessageInfoModel = try {
+        writer.searchItem(index + 1)
+    } catch (exception: Exception) {
+        EMPTY_MESSAGE_INFO_MODEL
+    }
+}

azure-communication-ui/chat/src/test/java/com/azure/android/communication/ui/chat/repository/storage/MessageRepositoryTreeStorageUnitTest.kt

@@ -0,0 +1,82 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.android.communication.ui.chat.repository.storage
+
+import com.azure.android.communication.ui.chat.models.MessageInfoModel
+import com.azure.android.communication.ui.chat.repository.MessageRepository
+import com.azure.android.communication.ui.chat.service.sdk.wrapper.ChatMessageType
+import org.junit.Assert
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.junit.MockitoJUnitRunner
+
+@RunWith(MockitoJUnitRunner::class)
+class MessageRepositoryTreeStorageUnitTest {
+
+    @Test
+    fun messageRepositoryTreeStorage_addPage_test() {
+
+        val storage = MessageRepository.createTreeBackedRepository()
+        val numberOfTestMessages = 170
+        for (i in 1..numberOfTestMessages) {
+            storage.addLocalMessage(
+                MessageInfoModel(
+                    id = i.toString(),
+                    content = "Message $i",
+                    messageType = ChatMessageType.TEXT
+                )
+            )
+        }
+
+        Assert.assertEquals(numberOfTestMessages, storage.size)
+        for (i in 1..numberOfTestMessages) {
+            Assert.assertEquals("Message $i", storage[i - 1].content)
+        }
+        // Assert.assertEquals("Message 16", storage[15].content)
+    }
+
+    @Test
+    fun messageRepositoryTreeStorage_removeMessage_test() {
+
+        val storage = MessageRepository.createTreeBackedRepository()
+        val numberOfTestMessages = 17
+        for (i in 1..numberOfTestMessages) {
+            storage.addLocalMessage(
+                MessageInfoModel(
+                    id = i.toString(),
+                    content = "Message $i",
+                    messageType = ChatMessageType.TEXT
+                )
+            )
+        }
+
+        storage.removeMessage(
+            MessageInfoModel(
+                id = "17",
+                content = "Message 17",
+                messageType = ChatMessageType.TEXT
+            )
+        )
+
+        Assert.assertEquals(numberOfTestMessages - 1, storage.size)
+        Assert.assertEquals(16, storage.getLastMessage()?.id?.toLong() ?: 0)
+    }
+
+    @Test
+    fun messageRepositoryTreeStorage_getLastMessage_test() {
+        val storage = MessageRepository.createTreeBackedRepository()
+        val numberOfTestMessages = 17
+        for (i in 1..numberOfTestMessages) {
+            storage.addLocalMessage(
+                MessageInfoModel(
+                    id = i.toString(),
+                    content = "Message $i",
+                    messageType = ChatMessageType.TEXT
+                )
+            )
+        }
+
+        storage.getLastMessage()?.id?.let { Assert.assertEquals(17, it.toLong()) }
+    }
+}